Effect of multidirection rubbing on the alignment of nematic liquid crystal

We have investigated the alignment properties of liquid crystals induced by multiple rubbing of the surfaces in different directions. Experiments were carried out using homeotropic and hybrid-aligned samples. It is experiment ally found that the alignment of the liquid crystals is along neither of th e rubbing directions, but instead lies along an axis intermediate between t hese two directions, and that the direction depended on the relative streng th of rubbing along the two axes. A model that assumed the grooves along tw o rubbing directions is proposed, and the relation between the orientation of the liquid crystal and the relative rubbing strength is analyzed. We fou nd that this model can explain the observed experimental results. (C) 2000 American Institute of Physics. [S0003-6951(00)02330-5].